current gen2 GM ecotec engines
L61- 2.2 n/a
LE5 - 2.4 n/a
LSJ - 2.0 s/c
LNF - 2.0 turbo SIDI
common features across all ecotec engines:
block structure has same girdle construction whereas the crank is sandwiched between two "halves" of the block. the oil pan is structural in construction. engine is all aluminum, and fully dressed is the lightest engines GM has ever produced. Manifolds are all directly interchangeable. Head design is different between engines, so cam swaps are only possible between the L61 and LSJ. the LE5 is not similar enough to the L61 and LSJ, and the LNF is completely different due to direct injection.
L61(2.2L)
140hp 150tq
86mm bore x 94.6mm stroke
the engine that started it all. first introduced to the Jbody in model year 2002 as the LS sport engine along side the 2200 OHV and 2.4 LD9. By the 2003 model year, it was the only powerplant available for the Jbody up until the end of production in summer of 2005.
-in the Jbody, the L61 comes with either the 4t40e or the getrag F23-M86 5 speed transmission.
-the L61 in the jbody has a 7 tooth reluctor wheel. the reluctor wheel is a cast section of the crankshaft that tells the ecu when to fire the ignition. This cannot be removed, swapped, or otherwise changed.
!!!THIS IS VERY IMPORTANT IF YOU PLAN ON RETAINING THE FACTORY ECU FOR ENGINE MANAGEMENT!!!
-rods and pistons are not known for strength, especially under boosted applications. Forged rods and pistons are not required, however encouraged (especially for turbo)
tidbits:
*the lsj supercharger and manifold is an ALMOST direct bolt-on for the L61. an adapter bracket for the throttle body and a part of the block by the pullies needs to be shaved down in order for it to be bolted on.
*all exhaust manifolds will physically fit on all ecotecs... however due to differing models' constructions, downpipes may be incompatible.
*the L61 in the Jbody has a return fuel injection system. All newer L61s as well as the LE5 and the LSJ use a returnless fuel injection system. the LNF uses a direct-injection system, much like a diesel
*as per GM racing research, the L61 head has a tendency to blow outward of #1 and #4 cylinders at around 500hp. This has yet to be confirmed.
the descendents of the (and including model year 2006 and higher L61 engines) L61 all adapted a "high resolution ignition system" that replaces the 7tooth reluctor with a 58tooth reluctor. this is what makes direct swaps to other ecotec engines impossible for a factory computer.
structurally, the LSJ and LE5 would be a direct swap due to the blocks being almost identical. The LNF has externally mounted accessories... namely, the high pressure fuel pump (500-2100psi) for the direct injection system, as well as an external water pump and may not fit in the Jbody engine bay.
LE5 (2.4L)
170hp 165tq
88mm bore x 99mm stroke
found in cobalt SS (non s/c), solstice, sky, malibu, HHR, and numerous other GM small cars
the big gun of the group, the 2.4 has an 88mm bore and a whopping 99mm stroke. It was also the first ecotec to implement variable valve timing.
tidbits:
-the LE5 has not only larger displacement, but slightly higher compression than the L61 at 10.4:1
-the LE5 (like the other siblings of the L61) comes with strengthened rods and crankshaft
-the LE5 also includes piston cooling oil jets that continously spray the underside of the pistons with oil to help keep them cool, and less prone to detonation.
LSJ (2.0L Supercharged)
200hp 205tq
86mm bore x 86mm stroke
found in: Cobalt SS s/c, Ion Redline
the cobalt ss/ ion redline engine proves very potent with the M62 supercharger. the head is cast by Saab, and has plenty of meat for very good port jobs, as well as includes sodium-filled exhaust valves which makes them appropriate for absorbing plenty of heat from the M62.
tidbits:
-despite popular belief, the LSJ head does NOT flow more than the L61 head. The LSJ head IS, however, stronger due to its casting and revisions from the L61 head, and does not require 'staking' at higher horsepower levels.
-piston cooling oil squirters for detonation resistance
LNF(2.0L turbo SIDI(Spark Ignition Direct Injection))
260hp 260tq
86mm bore x 86mm stroke
found in: Solstice GXP, Sky Redline
the newest addition to the ecotec family also happens to be the most powerful factory engine per liter ever produced by GM.
It utilizes a direct injection system that mounts the injector directly in the combustion chamber and allows for superior fuel economy and rapid fuel burn that allows for a higher compression ratio yet still minimizes the chance of detonation.
unless swapping over to a complete direct injection system, the LNF head, injectors and pistons cannot be used in any other ecotec
-direct injection (500psi-2100psi functional fuel pressure generated by mechanical fuel pump)
-piston cooling jets as all ecotec engines get (except the granddaddy L61)
